Electrical device



July 7, 1931. F. w. wALToN ELCTRICAL DEVICE Filed Jan. 6, 1927 FGJ.

NVENTO WALTO BY I ATTORNEY Patented July 7, 1931 UNITED STATES PATENT OFFICE FRANK WILLETT WALTON, F EAST ORANGE, NEW JERSEY, ASSIGNOR T0 WESTING- HOUSE LAMP COMPANY, A CORPORATION 0F PENNSYLVANIA ELECTRICAL DEVICE Application led January 6, 1927. Serial No. 159,269.

to the annulus of the bulb. The base or This invention relates to the manufacture of electrical devices and relates more particularly to devices such as radio tubes, incandescent electric lamps and the like.

An electrical device, such for example. as a radio tube, usually includes a container such as a glass bulb, a mount constituting the internal structure of the device and a base in which the several contact members, for

the passage of electrical energy to the interior of the bulb, are incorporated. It has heretofore been the practice to provide a mount which carries the various electrodes or elements of the device constructed in such u manner as to include a iared glass portion. This flared portion was united to the neck of the bulb by the application of heat. After the consolidation of the mount to the bulb, which is termed a sealing in operan tion, the bulb was exhausted either through tubulation upon the top portion of the bulb or through an exhaust tube provided as part of the mount.

The base portion which consisted of a thimble or shell having contact members incorporated therewith was then applied so as to enclose the neck or seal portion of the bulb and secured thereto by a suitable cementitious material of a heat resisting character.

The present invention aims to improve the structure of an electrical device by providing a base integral with and preferably of the same material as that of the bulb. In practicing my invention the usual form of mount may be employed and may be sealed to the inner wall of the neck of the bulb and in such position as to leave an extended portion or skirt of glass projecting in the form of an annulus depending from the united portions of the bulb and mount.

The base portion which may be in the form of a disk having the required number of contact members embedded therein and projecting therefrom, may then be applied disk is provided with a. circular ridge of a diameter equal Vto the diameter of the annulus and may then be united thereto by a fusing operation upon the application of heat by what may be termed a ring sealing operation.

Heretofore in the manufacture of audions. it has been the practice. to employ bases either of a wholly non-conductive material such as a condensation product or a metal shell with the contact members suitably insulated. In devices of the above character where extremely low amounts of electrical energy are employed, it is essential to provide a structure which will avoid any losses of energy and to reduce the. capacity effect. Where the base is wholly of a non-conductive material the desired result is approached; in the use of a metallic base, however, considerable losses occur tending toward inefficient operation of the device. Furthermore, in the use of a base such as the metallic or non-conductive sleeve construction a cementing operation is required and certain disadvantages follow since owing to the variation in the adhesiveness of the cement the base portion of the lamp often becomes loose with the result that the operativeness of the device is greatly impaired. Furthermore, a baking step is necessary to properly dehydrate or set the cement.

In the presenty construction. the union of the base to the bulb makes it possible to provide a complete unitary structure o'f a single material giving a device free from losses due to conduction and avoids the disadvantage of the separation of the base from the bulb.

An object ofthe present invention is, therefore, to provide an electrical device constructed substantially of a single material.

Another object of the invention is to provide a radio tube having the bulb fusibly 'united to the base.

Another yobject of the invention is to provide a radio tube constructed substantially of a plurality of vitreous parts fusibly united.

Other objects and advantages of the 1nvention will be more fully understood by reference to the accompanying drawings in which Fig. 1 shows a radio tube bulb having a mount sealed therein;

Fig. 2 shows an enlarged cross-sectional view of a base portion of a bulb, preferably formed from a vitreous material;

Fig.v 3 is a View similar to Fig. 1 but illus trates the application of a base to a bulb; and

Fig. 4 shows a radio tube complete as constructed in accordance with the present invention.

Although the present invention may be practiced in connection with various tubes, or electrical devices employing a bulb and base, as an embodiment of the invention, the

same is applied to a radio tube which, as shown in Fig. 1, may comprise a bulb 10r having the usual form of mount 11, comprising a flare tube 12 suitably consolidated with an exhaust tube 13. The flare tube and exhaust tube terminate in a compressed portion or so-called press 14 in which are embedded a plurality of support members 15, 16, 17 and 18. Mounted on support member 18 is the usual' plate or anode 19; the opposite end of the support member being connected to a leading-invwi re 21. A filament 22 is attached to support wires 16 and 17 which Wires are provided with conductors 23 and 24. Support Wire 15 has a grid 25, said support Wire having a conductor 26 connected thereto.

The mount 11 having the various electrodes supported thereto may be disposed in the bulb or envelope 10 so that the flared edge 27 of the mount is disposed adjacent to the interior surface of the bulb and so located that an annulus or skirt 28 is left at the lower portion of the bulb. By locally heating the bulb with suitable fires 29 and 31 the flare tube may be sealed to the bulb. After the mount has been sealed in the bulb, the bulb may be exhausted in the usual manner through the exhaust tube 13 which is then tipped off in the regular Way. The base. portion of the bulb in accordance With the present invention may be in the form of" a disk or plug 32 preferably of a non-conductive material such as a glass. The plug may be molded With the required number of tubular contact members 33, 34, and 36 properly positioned and the glass may be molded therearound` thus embedding the contacts in the glass and firmly securing them in position. It is obvious that although only three contact members are shown on the drawings that a base may be provided With any suitable number of contacts in accordance with the character of the device. The disk 32 may then be applied, as shown in Fig. 3 to the lower end of the bulb, the lead-in wires or conductors 21, 23,24 and 26 being threaded through the contact members in the usual manner. The disk may be so positioned that its upper edge 30 may be disposed in contact with edge 30 of the annulus 28. Suitable fires 37 and 38 may then be directed to heat the annulus and fuse the bulb to the base or dise 32. It will be understood thatI in the various sealing operations the 'bulb may be held or supportedin the usual support or head and rotated during the several sealing or fusing operations, or if desired, suflicient heat may be provided to surround the bulb and the rotating may be dispensed with. The method of supplying sufficient heat to perform the sealing operation is, of course, \\vell understood in the lamp making art and may be readily accomplishedy by those skilled therein.

By reason of the present invention a simple and effective method of producing an article such as a radio tube is attained and considerable advantage derived from the absence of the operations of applying a cement to a base and in securing the base to the bulb. The fusing of a base and bulb is attained by a single operation and inasmuch as the basing of the bulb with cement requires a subsequent baking operation, it` will be appreciated that a saving in both time and labor is effected and the cost of production reduced.

Although a preferred embodiment of the invention is shown and described herein, it is to be understood that modifications may be made therein Without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. The method of manufacturing an electrical device which comprises positioning a mount having a vitreous flared portion within a. bulb and in spaced relation to the perimeter of the mouth thereof, fusing the flared portion to the bulb, applying a base having a ridge of vitreous material to the perimeter of the mouth of the bulb so that the ridge is disposed in contact with the said mouth and in applying heat to fuse the base and bulb together.

2. The method of manufacturing an electrical device Which comprises positioning a mount having a fusible flared portion Within a bulb and in spaced relation to the perimeter of the mouth thereof, applying heat to unite the mount and bulb by fusion, exhausing the bulb, applying a base having a fusible edge portion to the mouth of the bulb so that the said edge is disposed in contact with the perimeter of the mouth and in applying heat to unite the base and bulb by fusion.

3. A radio tube comprising a bulb, a mount having a flared portion sealed to the inner wall of said bulb and spaced from the mouth of the bulb to provide an annulus and a base havin apertures to receive lead wires fused to sai annulus.

4. A radio tube comprisin a bulb, a mount having a flared portion sea ed to the inner wall of said bulb and spaced from the mouth thereof to provide an annulus and a base having a plurality of apertures to receive lead Wires and a ridge of substantially the same diameter as the ed e of said annulus and united thereto by a sing operation.

In testimony whereof, I have hereunto subscribed my name this 3rd day of January,

FRANK WILLETT WALToN. 

